Abstract：In order to solve the problem of high computation complexity of narrow transition band filter bank, an odd-arrangement non-maximally decimated efficient structure with narrow transition band filter bank based on frequency response masking (FRM) is proposed. Firstly, when the prototype filter of this structure is designed, the FRM filter of the upper arm is obtained through the interpolated prototype filter. Secondly, the complementary filter of the lower arm is obtained by the delay signal subtracted from the interpolated prototype filter. Then the masking filter is used to shield the mirror caused by the interpolated filter. Finally, the desired FRM filter is obtained. The improved structure is simulated by MATLAB, and the simulation results verify the correctness of this improved structure. This efficient structure saves 80% of the multiplier resources compared with the polyphase filter bank architecture. Because the decimation module is located at the front of this improved structure, the limited condition of the sampling rate of the system is reduced and it can be directly used in the high-speed sampling system.